Numerous devices (e.g., implantable medical devices (IMDs) electrochemical cells, etc.) are hermetically sealed. Hermetically sealed containers prevent liquid from contacting electronic components within a device. To connect with the electronic components, a feed-through assembly is inserted into a portion of the container.
A typical feed-through assembly consists of a conductive part (e.g., wires etc.), a ferrule, an insulator member (e.g. glass, ceramic etc.), and a seal. The ferrule includes an aperture configured to receive the insulator member. A seal is located between the ferrule and the insulator member. An eyelet, slipped over wires and seated into the insulator member, protects the insulator member from weld splatter. Weld splatter occurs during a subsequent welding operation to close the container. Failure to properly seat the eyelet into the insulator member may result in a defective feed-through assembly.
Presently, a semi-automated method seats an eyelet into the insulator member. In this operation, a device holds a feed-through subassembly in position. The wires extend from the feed-through subassembly in an upward direction while the eyelet is slid over wires and into the insulator member. The feed-through assembly then undergoes a welding operation to close the container. The equipment for the welding operation holds the feed-through assembly such that the wires are pointed down. An eyelet that is not properly seated may slip off during the welding operation. Once the eyelet slips from its original position, the insulator member is exposed to random weld splatter resulting from a subsequent welding operation. A large amount of the devices are deemed defective due to weld splatter. For example, some production runs produce 50% defective feed-through assemblies. Defective feed-through assemblies are typically discarded resulting in lost wages and material. It is therefore desirable to have a method that overcomes the limitations associated with a conventional feed-through assembly process.